Sildenafil ameliorates left ventricular T-tubule remodeling in a pressure overload-induced murine heart failure model.

AIM: Sildenafil, a phosphodiesterase 5 (PDE5) inhibitor, has been shown to exert beneficial effects in heart failure. The purpose of this study was to test whether sildenafil suppressed transverse-tubule (T-tubule) remodeling in left ventricular (LV) failure and thereby providing the therapeutic benefits. METHODS: A pressure overload-induced murine heart failure model was established in mice by thoracic aortic banding (TAB). One day after TAB, the mice received sildenafil (100 mg·kg(-1)·d(-1), sc) or saline for 5 weeks. At the end of treatment, echocardiography was used to examine LV function. Then the intact hearts were dissected out and placed in Langendorff-perfusion chamber for in situ confocal imaging of T-tubule ultrastructure from epicardial myocytes. RESULTS: TAB surgery resulted in heart failure accompanied by remarkable T-tubule remodeling. Sildenafil treatment significantly attenuated TAB-induced cardiac hypertrophy and congestive heart failure, improved LV contractile function, and preserved T-tubule integrity in LV cardiomyocytes. But sildenafil treatment did not significantly affect the chamber dilation. The integrity of LV T-tubule structure was correlated with cardiac hypertrophy (R(2)=0.74, P<0.01) and global LV function (R(2)=0.47, P<0.01). CONCLUSION: Sildenafil effectively ameliorates LV T-tubule remodeling in TAB mice, revealing a novel mechanism underlying the therapeutic benefits of sildenafil in heart failure.

Recommendations on screening mammography in patients with ventriculoperitoneal shunts and deep brain stimulation.

Insertion of ventriculoperitoneal (VP) shunt and deep brain stimulation (DBS) are common neurosurgical procedures. Concerns have been raised regarding the safety of mammography in this patient cohort due to the risk of damaging the VP shunt tubing or DBS implantable pulse generator, and the degradation in mammography image quality secondary to the implanted devices. Based on a review of the current literature, the authors propose that mammography is safe in patients with VP shunts and DBS, and should be performed routinely as a part of population screening.

Familial intracranial ependymoma mimicking an extra-lesion: A case report and review of the literature.

Familial occurrence of intracranial ependymoma, in the absence of neurofibromatosis type 2 (NF2), is very rare with only a few cases reported in the literature. We report a 62-year-old man, who presented with a posterior fossa ependymoma with the majority of the lesion in the cerebellopontine angle, mimicking an extra-axial tumour. His two brothers also had 4th ventricular ependymomas requiring surgical resection. Such cases add weight to the suggestion of a genetically predisposing mutation in familial cases of intracranial ependymomas. Further genetic testing may help to elucidate the location of the genetic abnormality in patients with non-NF2 familial intracranial ependymomas and promote a better understanding of this rare pathological entity.

Secondary Diffuse Choroid Plexus B-Cell Lymphoma: Case Report and Review of Literature.

BACKGROUND: Central nervous system (CNS) relapse is an uncommon complication of diffuse large B cell lymphoma and is associated with significant mortality and morbidity. It is becoming a more prevalent pathologic entity in the rituximab era. Our case provides insight into the pathophysiology, diagnosis, prevention, and management of secondary intraventricular CNS lymphomas. CASE DESCRIPTION: We report an unusual case of a 64-year-old man who presented with an isolated secondary CNS lymphoma involving the choroid plexus in a diffuse pattern. He initially presented with obstructive hydrocephalus from diffuse choroid plexus lesions and was commenced on systemic therapy after confirmation of diagnosis via samples obtained from an open biopsy. CONCLUSIONS: This case highlights the lack of high-quality evidence behind the use of high-dose intravenous methotrexate as CNS prophylaxis. The case provides additional insight into the pathophysiology of intraventricular CNS lymphomas and the importance of establishing a histopathologic diagnosis via an open biopsy before the administration of high-dose steroids.

Tension pneumocephalus from skull base surgery: A case report and review of the literature.

BACKGROUND: Tension pneumocephalus from skull base surgery is a rare occurrence that mandates urgent neurosurgical attention. CASE DESCRIPTION: We describe a case of tension pneumocephalus secondary to an endoscopic endonasal resection of an adamantinomatous craniopharyngioma and how it was successfully managed at our institution. CONCLUSION: Our experience reflects that definitive treatment of tension pneumocephalus is required with multilayered dural repair, but temporising measures should be used immediately to prevent neurological deterioration prior to the definitive repair.